The present invention relates to test tubes in general, and more particularly, to a manually operated apparatus for inserting pump mechanisms into test tubes which are sealed by a closure such that the contents of the test tube may be discharged without removing the closure from the test tube.
Heretofore it has been known to provide a resilient closure or rubber stopper for a container and to discharge the contents of the container by using a pump mechanism which establishes inlet and outlet flow paths through the closure. Air pressure through the inlet path pressurizes the interior of the container and causes the contents to flow through the outlet path. Pump mechanisms of this type are, of course, known and, prior to the present invention, the establishing of the fluid flow paths was accomplished by puncturing the closure with a hand-held pump mechanism.
There are, of course, numerous concerns when puncturing the closure of a test tube by hand. A fundamental problem, of course, is that a test tube is formed of glass and, therefore, is subjected to breaking if excessive forces are used.
Equally important is the need to align the direction of force relative to the elongated axis of the test tube to provide proper positioning of the pump mechanism. Furthermore, the amount of force necessary to penetrate or puncture the test tube closure is minimized if the direction of the inserting force is parallel to the longitudinal axis of the test tube rather than at some angle to the longitudinal axis of the test tube.
Yet another problem in connection with attaching pump mechanisms to test tubes by hand is the difficulty in handling such mechanisms because of their relatively small size.
A still further problem is the amount of time and labor involved in attaching pump mechanisms to test tubes if each pump must be attached by hand in sequence, on an individual basis, rather than attaching a plurality of pump mechanisms simultaneously to individual test tubes.
Avoiding contact with the specimen in the tube may also be an important consideration. Insertion of the pump mechanisms by hand may pose a risk of such undesirable contact occurring if test tube breakage should occur.
In allowed copending U.S. patent application Ser. No. 07/383,339, a pump inserter is disclosed for the efficient automatic insertion of a large number of pump mechanisms into test tubes. However, in some circumstances, the use of such an apparatus may not be most efficient or cost effective, such as when only one or a small number of test tubes are involved.
Thus, the inventors recognized that there existed a need for a relatively inexpensive manually operated pump inserter for test tubes.